ISSN (International Standard Serial Number)
The ISSN (International Standard Serial Number) serves the short unmistakable identification of sequentially appearing publications, e.g., magazines. The ISSN is nearly similar to the ISBN for books.
The ISSN exists of 8 digits, which are split by a hyphen in two groups of 4 digits. The hyphen itself has no meaning for the code. It only serves as an optical difference to other codes. The first 7 digits display the real ISSN number. The 8th digit is the check number which is computed according to Modulo 11.
An ISSN barcode is created using the EAN-13 symbology with a special prefix. So the ISSN is a special form of the EAN-13 code.